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[edit] Effectiveness vs Cost-Effectiveness

This exchange was cut from ImperfectlyInformed's talk page. Please post article issues to the article talk page.

Hi II, I agree that an older study should not replace a newer one. However, I am concerned that the negative bits are picked out of the mostly positive information in these studies in order to cast doubt on the subject of water fluoridation. The phrase you replaced needs a little more explanation, in my opinion, about how it is refering to the fact that most people are exposed to more sources of fluoride than just water and that this hasn't been studied sufficiently. The article seems terribly biased against water fluoridation in general. --—CynRN ^(Talk) 14:59, 6 October 2008 (UTC)

The statement is regarding the cost-effectiveness of fluoridation rather than just the effectiveness. Anyway, the article, when done well, should be fairly critical of fluoridation because the most reliable estimates, such as the University of York review, are critical. I agree that the history section is dependent upon an unreliable website, incidentally. II | (t - c) 17:29, 6 October 2008 (UTC)

the article, like all Wikipedia articles, should not be "fairly critical" of fluoridation, highly critical, or uncritical -- or take any other position at all. It's not our place to render scientific or economic judgments. The article, i hope, will present the sources, and leave the reader to evaluate them. It is necessary to be careful to be fully representative, and not cherry-pick the studies which support ones point of view. You can give the dates, but not say that something supersedes unless there is a truly authoritative source to quote for that. DGG (talk) 03:58, 9 October 2008 (UTC)

If the best sources are fairly critical, then the article will be fairly critical. Who said it was my judgment? It was the judgment of the University of York's systematic review, published in the British Medical Journal. Per WP:MEDRS, that source is better than the CDC, which is tertiary, and truly is the authoritative source. Similarly, National Academy scientists were rather critical of the practice in the 2006 book on the subject. II | (t - c) 07:57, 9 October 2008 (UTC)

[edit] Tags at top of article

I saw the {{globalize}} and {{POV}} tags at the top of this article, came to the talk page to find discussion about them, and basically came up dry. I just now read the article for the first time and don't see significant problems in either area. For now I've removed the tags. Anyway, tags are not supposed to reflect a long-ago objection by an editor: they're supposed to reflect a continuing process to improve the article. Eubulides (talk) 20:09, 7 November 2008 (UTC)

[edit] Major restructuring

To be blunt, this article was written like a conspiracy-theorist's newsletter: disconnected paragraphs of irrelevant details full of weasel words and unnecessary opinions from individuals and advocacy groups. I've made an attempt to reduce that problem, but more work needs to be done (hence the cleanup tag). Opinions should be summarized on their own page.

I moved the summaries of mid-20th-century research to a special subsection of "History," put them in chronological order, and cleaned up some out-of-place advocacy. I was tempted to delete these paragraphs altogether, as they're probably irrelevant, but I didn't want to make that decision alone. If anyone else agrees, I'd encourage you to follow through. I also consolidated fluorosis into the section on health effects, since it has its own article.

There are a lot of ppm numbers thrown around, perhaps too many. The single most important one is absent: what concentration of fluoride is actually used in fluoridated water? If it's significantly and consistently far lower than that at which side effects occur, then much of this material doesn't belong here since it doesn't involve intentional fluoridation of water.

P.S. I didn't notice that I wasn't signed in when I edited the article itself, so the changes are attributed to an IP address. Sorry. Epistaxis (talk) 01:34, 10 November 2008 (UTC)

You may want to try that again, minus the vague allegations and rhetoric. Expert opinions from toxicology and dentistry researchers who have taken a long look at the scientific literature certainly belong on this page. And it is clear that you didn't read very carefully (or know much about the subject) if you didn't get the number which water is fluoridated at, which was stated clearly. II | (t - c) 09:59, 10 November 2008 (UTC)

The edits of these wise self-styled "experts" and guardians of Wikipedia´s "quality standards" make it obvious again that contributing to this article is a waste of time. Tren (talk) 20:56, 10 November 2008 (UTC)

I made these changes with the intention of improving the article and making it more encyclopedic. Please review my comments carefully. And in case that's still not clear: this article includes a lot of detail that, even if factual, is not informative about the issue. This includes a history of research studies performed in the mid-20th century. Few studies are noteworthy for being studies. What is noteworthy is the result of a study, as it pertains to the topic, and surely there are is a more recent study, or even a survey of studies, that could be cited instead.

Also, upon another close inspection of the article, the standard amount of fluoridation is still not there. Here is a list of the fluoride concentrations mentioned in the article:

• 2 to 13.7 ppm: contamination in Colorado, 1931
• 2.8 - 3.9 ppm: Amarillo 1936-7 (Wichita Falls is missing)
• 1 mg per day / 1 ppm: 1942 optimal fluoride
• 0.7 ppm to 1.2 ppm: present (?) CDC recommendation
• 1 ppm: 12.5% of people have aesthetic concerns about fluorosis (possibly the same number for decrease in cavities and decay, but this is not made clear and that number may be omitted)
• 0.7 – 1.2 mg/L: "above the commonly recommended dosage," causing side effects (or is this stated unclearly?)
• 1 – 3 mg/day: intake calculated by a Wikipedia author (?) based on recommended water consumption
• 4 mg/L: EPA maximum contaminant level, recommended by NRC to be lowered
• 1.4 – 2.4 mg/L: EPA MCL before 1985
• 1.5 mg/L: WHO caution
• 10 ppm: bone damage
• 0.07 – 1.2: optimal (WHO again?)
• 2 mg/L: NRC bone risk unknown
• 1 mg/L to 4 mg/L: differential known to increase risk
• 12 mg/day: expected to cause kidney side effects
• 4 mg/L: can possibly lead to the above intake
• 23 mg/day: some studies suggest negative liver effects
• 0.36 ± 0.15 mg/L (range 0.18-0.76 mg/L), 2.47 ± 0.79 mg/L (range 0.57-4.50 mg/L): areas compared for IQ in unpublished (?) studies

Not one of these is clearly stated as a typical fluoridation level introduced into a public water supply. And in an encyclopedia, as opposed to a medical reference book, I think most of these facts could be explained without having to specify the exact numbers; truly curious readers can follow the citations. Epistaxis (talk) 06:10, 11 November 2008 (UTC)

Epistaxis, I'm sorry if this sounds rude, but look at all those values you cited. Do you really think the fluoride level found naturally in 1931 Colorado water is the amount used? Now zero in on the present CDC recommendation, which differs "depending upon air temperature". Do you think that might mean something? It is stated in the second sentence on the cost-benefits section. In the possible health effects section, the section which you eliminated, it is stated again in the first sentence: "Negative health effects are generally associated with fluoride intake levels above the commonly recommended dosage, which is accomplished by fluoridating the water at 0.7 – 1.2 mg/L (0.7 for hot climates, 1.2 in cool climates)". So we have clear evidence that you didn't even read that section! I'm sorry if this sounds rude, but read before you make a big fuss! II | (t - c) 19:58, 11 November 2008 (UTC)

I'm pretty sure that the 0.7-1.2 ppm (mg/L) level is the general standard for municipal water supplies with added fluoride. The devil enters with the details: studies of natural water supply in excess of this level are included, in many cases with no 3rd-party comment on their methodological rigour; there is a valid argument that variation in daily water consumption (among water enthusiasts or low body-weight individuals, for example) could result in excessive fluoride intake, and this can be compounded by dietary intake. The current US regulation permits up to 4ppm I think, and this is a bone of controversy - even though no municipal facility is known to fluoridate to that level, it's within standard, so is (apparently) a legitimate target for commentary. Additionally, anytime there's a big tank of fluoride compounds hooked up to a water pipe, there's a risk that the entire tank can empty into the pipe, with toxic effect - again, a legitimate target of criticism.

Inclusion of the studies showing toxic effects at extremely high doses probably don't belong here, as we do have a separate article to describe the toxic effects. The studies which are not subject to 3rd-party commentary (review article or meta-study) are particularly on the edge. Here's a thought though - would it be possible to re-sort these data (maybe in a table) along a gradient of the fluoride level? Then the reported effects could be viewed by increasing dosage, and the "standard" and "maximum US allowable" dosage levels could be shown in-line. Franamax (talk) 06:50, 11 November 2008 (UTC)

Something like the above, only far, far less lame... Franamax (talk) 07:09, 11 November 2008 (UTC)

That would be an improvement over sprinkling these data throughout the text, but I still question whether the article should contain so many numbers at all. This isn't a medical reference; to treat it like one is at best irrelevant and at worst physically harmful. Maybe it should just state the recommended dosage and refer to "elevated" concentrations for the health effects etc. Curious medical scholars ought to follow the links to the primary sources anyway. --Epistaxis (talk) 08:24, 11 November 2008 (UTC)

First, there are 4 experts on fluoride and toxicology who say that some of the effects occurring at 2 – 4 ppm are relevant to municipal water fluoridation at 0.7 to 1.2. That's why some of this stuff is in here. The dosage is uncontrolled. Plus, it is nice to put a summary of the research up so that people know. In some cases it should qualm fears, since liver damage doesn't seem to happen until you get 23 mg/day (although the actual studies of that are slim). The osteosarcoma link occurs at the CDC's recommended levels, by the way. Also, the EPA standard on what can occur in drinking water (4 ppm) is also relevant, since natural fluoride is used as a substitute for added fluoride. II | (t - c) 19:58, 11 November 2008 (UTC)

What about this: "The CDC recommends fluoridation between 0.7 and 1.2 ppm, though the EPA allows higher levels for naturally occurring fluoride." "Typical fluoridation levels are between X and Y ppm" (still no source for this). "Higher levels of fluoridation can increase the incidence of fluorosis." "Extreme levels may lead to liver damage." "Osteosarcoma may result even at the recommended levels." This way, only the two most relevant figures are given, but all the important information is still there. If a physician really wants specific data or a survey of the latest literature, she probably isn't coming to Wikipedia for that information, and we have links to the sources for those kinds of details anyway. As I said before, for anyone other than an expert, such esoteric content is at best unencyclopedic, and at worst dangerously out of context. --Epistaxis (talk) 08:09, 12 November 2008 (UTC)

Let's hear what a few other people have to say on the issue. I don't think it is dangerous to summarize the conclusions of the National Research Council in this article. There's a lot of misinformation floating around, and this is not it. I also don't think it is amiss to cite conclusions of the NAS toxicology researchers arrived at after reviewing the evidence, although 2 of them aren't really that relevant. John Dull and Kathleen Thiessen's comments are the most relevant. Also, I certainly don't agree with you that fairly accurate summaries of the toxicological literature regarding fluoridation are "esoteric content" which are "at best unencyclopedic". Wikipedia is not dumbed down. We give people the dirty details and the numbers, especially when those numbers are simple and easy to understand. Take a look at the mathematics articles sometime. II | (t - c) 06:00, 20 November 2008 (UTC)

I agree with Epistaxis that there is waaaay too much detail about individual research studies, both in Water fluoridation #Early studies and in Water fluoridation #Possible adverse health effects. And as per WP:MEDRS and WP:RS we should be citing secondary reviews, not primary studies directly. This article certainly should not be citing ancient primary studies like Dean 1934 (!), nor should we be citing marginal speculative studies like Coplan et al. 2007. Stuff like that should be moved into a more detailed article on water fluoridation research, or perhaps into the opposition article. Eubulides (talk) 06:16, 20 November 2008 (UTC)

[edit] Change to lead overemphasized prevalence

This change to the lead has a couple of problems:

• It emphasizes the prevalence of water fluoridation all out of proportion to its weight in the body. The topic is only a small part of the body, and should not consume half the lead. A brief statistic of worldwide use should suffice.
• The cited source does not support the phrase "since the 1950s".
• I made this further change to try to improve the lead further.

Eubulides (talk) 09:15, 19 November 2008 (UTC)

The geographical prevalence is fundamental to providing a broad overview of the topic. Per WP:LEAD: "The lead should be able to stand alone as a concise overview of the article. It should establish context, explain why the subject is interesting or notable, and summarize the most important points—including any notable controversies that may exist." If you're going to mention that the United States routinely does, you're obligated to mention the fact that other developed nations do not in order to avoid misleading the reader. I hate to assume bad faith, but it seems as if you're trying to mislead the reader, especially since a common misconception in the United States is that water fluoridation is standard practice among developed nations. Let's hear what other people have to say. I may start a thread over at WP:NPOV/N and WP:MED to see if we can get an audience. II | (t - c) 09:23, 19 November 2008 (UTC)

Saying that 5.7% of the world's population drinks fluoridated water makes it pretty obvious that it's not that common worldwide, no? If you prefer a different concise wording to establish the contrast, please suggest it; but detailed statistics about this country and that region are out of place in the lead, due to the weight problem mentioned above. Eubulides (talk) 09:31, 19 November 2008 (UTC)

Well, no. Call me pessimistic, but I think a lot of American readers who consider themselves educated could take away from that statement that "oh, the US and the rest of the developed world fluoridates water, and the developing world doesn't". I don't think most people have a ballpark understanding of world population numbers. I still think the lead could be added to, especially in terms of evidence. And the CDC is a poor source, considering that its been promoting fluoridation for decades. The cost-benefits / efficacy section should give start with the York review. I may do that tomorrow. II | (t - c) 09:38, 19 November 2008 (UTC)

"Wikipedia is not dumbed down". And even if it were dumbed down, I doubt whether lots of American readers would be so dumb that they would think the developed world constitutes only 5.7% of world population. The revised wording still spent waaaaayy too much weight on prevalance compared to its weight in the body. I made this change to try to bring it back into balance. Eubulides (talk) 06:29, 20 November 2008 (UTC)

Having watched the edit wars for several years...
Would it not be more encyclopaedic to have the first paragraph explain that we are talking about a subject that should fall into the Category:Policy, for that it all it is (and all it can be) until the missing scientific research is conducted.
As it is now (starting with bold assertions) makes it sound like the benefits (or harms) are set in scientific concrete and is thus ensures the edit war continues. I blame med schools for instilling un-realistic view of how health polices come about and why and what is involved in their formulation – (but that's another matter). Having a separate article for the 'controversy' also guaranties polarisation, rather than the coming together and laying out of the known with the unknown.
Whilst some editors are left free to confuse the processes of agreeing policy and the process of scientific evaluation (or systematic review) in their minds, so the article will reflect that confusion don't you think? By always viewing it as just another policy however, it will then be a little easier to create text that explains simply why some countries change their water treatment policies from time to time -without another editor flagging it as POV in respect of one dogma or the other. The amount of 'weight' to give each aspect might also be a little easier to judge. I have seen a lot of editors generate acres of text over this article over the time I have been watching it and much time seems to be spent going back and forth and round and round. Maybe this different approach might help to anchor it.--Aspro (talk) 12:23, 20 November 2008 (UTC)

[edit] Major copyright infringement

This edit by 67.135.62.118 (talk • contribs • info • WHOIS) was a massive copyright infringement from here. I reverted it. Please don't do that. Eubulides (talk) 22:19, 30 November 2008 (UTC)

[edit] Evidence-basis changes

This set of edits has some problems:

1. It summarizes the York review as saying "there are no clear adverse effects aside from fluorosis". However, the earlier sentence that summarizes fluorosis talks about more-severe cases caused by too much fluoridation. A naive reader would easily conclude that typical fluoridation would cause these more-severe symptoms.
2. The York study doesn't merely say there are no clear adverse effects. For the most important and well-studied effects (cancers, bone fracture) it says that the best available evidence shows no association.
3. At this point, it would be better to cite Yeung 2008 (PMID 18584000) rather than the York review, done in 2000 (PMID 11021861). The reviews' conclusions are the same, from the point of view of the lead, but Yeung has more-recent data.
4. The set of edits alters the lead to say that WF has been "contentious" and that this is "generating an opposition to water fluoridation". But the contentiousness is not generating the opposition: it's the other way aroudn. The contentiousness is the result of proponents and and opponents arguing.
5. It alters the lead to cite an older source (McNeil 1985) that is not cited in the body. I don't see any reason to cite this older source in the lead; the claim was already well-sourced by a higher-quality and more up-to-date source (Cheng et al. 2007, PMID 17916854). Certainly the lead should not be citing sources that the body does not cite.
6. The set of edits alters Water fluoridation #Evidence basis so that it starts off with a criticism of the quality of the research. However, reliable sources don't start off that way. For example, Yeung's summary of findings (Table 3) starts off "Existing evidence strongly suggests water fluoridation is beneficial at reducing dental caries." We should lead with the primary results, and talk about quality of data later.
7. For sources that are relatively supportive of water fluoridation (the CDC), it gives in-text attribution ("the CDC has attributed"). For sources that are relatively critical of water fluoridation (the York review), it merely states their conclusions without attribution. This gives greater weight to critics of fluoridation, which is a POV presentation.
8. It give great weight and considerable to the York review's statement that it found no cost-effectiveness evidence that met its standards, and it removed the CDC's statement that fluoridation is cost-effective.
9. It removed the mention about the equitability of water fluoridation.
10. It presents the CDC's conclusions and then immediately argues with then ("but this has been disputed by others"). It does not do the same for the York conclusions.

I have attempted to work around some of these problems with this edit and with this edit. Eubulides (talk) 21:44, 21 December 2008 (UTC)

Numbered bullets for easier discussion.

1. I don't mind saying most of fluorosis is mild in order to avoid confusing the reader. It may be better to just use numbers in the body: 48% are expected to have fluorosis, with 12.5% having it at the aesthetic concern level. You may also want to mention the precautions that Australia has taken. I can't recall what Yeung said about how effective that was.
2. It is important to note that distinction. It is also important to note that the York review's conclusion on negative effects aside from bone fracture and osteosarcoma is that the studies "provide insufficient evidence on any particular outcome to permit confident conclusions" (14). The lead should specifically note where the high-quality evidence has been directed.
3. In general, we're trying to cover all the angles of information in the interests of being comprehensive. The Yeung review includes only study more than the York review, so while it is more up to date, its benefits over York should not be exaggerated. Yeung itself says that it largely depended upon the York review. If the Yeung review doesn't cover an angle covered by the York review, we cite the York review. If the two disagree, we note their disagreements. Let me know what your thoughts on this approach are. Since the Yeung review avoids discussing evidence quality and does not contradict the York's reviews conclusions, the York review should be cited.
4. Isn't this like what came first, the chicken or the egg? It seems obvious that the opposition movement would come after certain people contended that fluoridation has not been proven to be justified. Please restore.
5. OK.
6. If we're starting off a section on evidence basis, starting with a summary of the quality seems reasonable. Yeung avoids discussing quality, so the York review was used. I disagree with your conclusions here. We should lead with the quality and the results, since the results are informed by the quality. Anyway, I don't mind how it looks now.
7. The York review is obviously more reliable than the CDC, as it is independent. The CDC has been promoting fluoridation for 50 years and is defensive if someone says the evidence isn't as good as they've been saying. Thus, this is appropriate. However, if you want to attribute the York review's claims, feel free to do so.
8. Again, conflict of interest and reliability. The CDC not only has a conflict of interest, it is also unpublished and thus not subject to peer review. Stating that the reduction in caries in the US can be attributed to water fluoridation could probably not pass peer review. The CDC's cost-effectiveness is based on an unpublished workshop in 1989 which found little high-quality evidence, even before the York's critical review (which changed the dialogue from 50% reduction to 15%). The CDC source here is dated and unreliable.
9. I'm not seeing where I removed it. Anyway, the York review was only able to find C level evidence on the equitability. It's more up to date and more independent. Its conclusions (which are not that there's no evidence) are on page 14. Cite those before the CDC.
10. 5 European nations with neither water nor salt fluoridation have lower DMFTs in 12-year olds than the US. Overall, 10 European countries with no water fluoridation have lower DMFTs than the US. The WHO data is here. Fluoride Action Network has put in a graph her, along with snippets from various reviews. Cheng correctly points out that attributing the reduced cavities to water fluoridation cannot be justified, regardless of what the CDC says. Please put back the fact that this is disputed.

Looking through the changes, I don't have that big of a problem with them, but I don't like the way you've obfuscated how the research has gone. We should actually be getting a bit more specific by mentioning that most of the evidence is before and after studies, which is why the York review criticized it so much. There are no RCTs, even though RCTs are theoretically possible. Describing particular studies, when there have been a few key studies, is good, and you've eliminated that. The York review needs to be given more weight than the CDC in terms of equitability and cited when Yeung cannot be. The lead of effectiveness, that "water fluoridation most effective and socially equitable way to achieve wide exposure to fluoride's cavity-prevention effects" is untenable. It doesn't matter whether Yeung says it, it is just far too questionable and disputed to state so matter-of-factly. The York review had a different interpretation of the same evidence, so its interpretation needs to be included. The fact that the CDC's attribution of lower cavities to water fluoridation is highly questionable needs to be included. I don't understand why or how you can, in good faith, justify removing Cheng and Diesendorf's dispute of the claim. If we can't agree on these things, then we'll have to do some dispute resolution.

1. Yes, it might make sense to give the York numbers for fluorisis in the body of the article.
2. It's not clear that the lead needs to go into details about the difference between no-association and not-enough-evidence, simply because the York review makes that distinction. That sort of detail seems more appropriate for the body. At the level of abstraction appropriate for the lead, almost all major dental and health organizations either have found no association with adverse health effects or support water fluoridation. The lead shouldn't imply anything different, and shouldn't go into a lot of detail that makes it sound like there might be something different.
3. I don't know of any material area where the Yeung review disagrees with the York review. However, the Yeung review is more up to date, covers more material, and comes to more conclusions than the York review does. The Yeung review largely defers to the York review for the effectiveness of water fluoridation, but it also notes the issue of the halo effect, and for dental fluorosis it also relies on Griffen et al. 2001 as well as 11 other additional studies (not covered by the York review). I don't see any reason to omit results from the Yeung review in these areas.
4. If we can't show that contention led to opposition, we shouldn't assert that in the lead. (Just as we shouldn't assert the chicken came before the egg....)
5. OK.
6. If you don't mind how it looks now, let's move on to the more-important matters.
7. It is not at all clear that the difference (if any) in reliability between the York review and the CDC source requires in-text attribution for the CDC but not for York. The CDC has not existed for 50 years, so it can hardly be said to have been promoting anything for 50 years. The CDC is generally recognized as a reliable source on public-health issues, and we shouldn't be inserting text to undermine or dispute its results unless there is a conflict among reliable sources on what we are summarizing here, which there doesn't appear to be.
8. Claims that the CDC have a conflict of interest in this area are fringe claims, and the article should not be based on them. That sort of argument belongs in Opposition to water fluoridation, not here. There is no controversy among reliable sources for any claims in Water fluoridation that are currently sourced by the CDC, so there's no need to have in-text attribution for any of those claims.
9. The point about equitability is now sourced by Yeung 2008, not by the CDC.
10. The point about European results being different is addressed in the body, and is sourced by Burt & Tomar 2007, not by the CDC. I don't see anywhere that Cheng et al. 2007 (PMID 17916854) says anything like "attributing the reduced cavities to water fluoridation cannot be justified, regardless of what the CDC says"; perhaps you could supply an exact quote?

The followup remarks seem to be arguing against the CDC's conclusion that water fluoridation is associated with fewer cavities. But the York and Yeung reviews come to the same conclusions. I don't see why the article should be arguing against this point: it's the mainstream opinion. As per WP:NPOV we should base most of the coverage on the mainstream opinion, not on the fringe opinion that fluoridation does not help against tooth decay. Diesendorf 1986 (PMID 3523258) is way, way, dated; we should not be relying on 20-year-old sources for medical facts and figures, especially when up-to-date sources are available. Cheng et al. 2007 (PMID 17916854) is cited six times in the article; I'm not sure what removal is being talked about here. Eubulides (talk) 08:37, 22 December 2008 (UTC)

Please try not to mischaracterize my remarks. I've never edited to take out statements that water fluoridation reduces cavities, and I said just a second ago that I'm fine with the intro in the Evidence Basis section. What I do oppose is turning the effectiveness section into a fluffy, shallow promotional section. The York review stated that there is not limited evidence on the equitability or the cost-effectiveness. There is some evidence, yes, but it stated that it should be viewed with caution. Clearly, then, McDonagh seems to disagree with Yeung. Or maybe there is no disagreement, and the other public health measures have even less evidence, which allows Yeung to use that superlative. Either way, the evidence quality needs to be presented. Yeung includes only 1 relevant extra study (though categorized as Level IV), which actually found that caries did not increase after fluoridation was discontinued, so there's not a major reason to shut out York's differing interpretation of the evidence. Discussion of the quality of the efficacy should also not be ignored or relegated to a vague statement. In any other medical article, you would certainly be arguing that the quality of the evidence should be taken into consideration when discussing effects. Here's a pop question for you: how many of these before and after studies looked at confounding effects at all (toothpaste use, mouthwash, ect.)? I'll save you time: none. There's a reason the York review was critical and stated that it was "unable to discover any reliable good-quality evidence in the fluoridation literature world-wide".

Burt & Tomar 2007 speculate, without any sources, that better access to dentists for children in Europe explains the decline in cavities. That is just speculation and opinion if there are no sources using data to back it up. Cheng et al write that "[a decline in caries] has occurred regardless of the concentration of fluoride in water or the use of fluoridated salt, and it probably reflects use of fluoridated toothpastes and other factors, including perhaps aspects of nutrition". Similarly, Aoba et al 2002, states that "the dramatic decline in dental caries which we have witnessed in many different parts of the world has occurred without the dental profession being fully able to explain the relative role of fluoride in this intriguing process". II | (t - c) 01:29, 23 December 2008 (UTC)

• Sorry, I don't know what is meant by "mischaracterize my remarks". I don't recall claiming that you "edited to take out statements that water fluoridation reduces cavities", or anything like that.
• There was nothing fluffy or promotional about the effectiveness section. It accurately summarized recent, reliable reviews in the area.
• The York review does not disagree with Yeung on any substantial point. It certainly does not disagree on the issues of equitability and cost-effectiveness. The York review itself (McDonagh et al. 2000, PMID 11021861) never mentions equitability, cost-effectiveness, or caution. The full York report (which is not peer reviewed) says that they briefly researched studies of equitability only in England (not worldwide), and says that cost-effectiveness was outside the bounds of the review. No doubt this explains why issues of equitability and cost-effectiveness were not addressed in the York review itself.
• Water fluoridation gives detailed statistics from the York review, including ranges; surely this should suffice for "quality of the efficacy". It's certainly not vague.
• I don't see how York has a "differing interpretation of the evidence" from Yeung. On points where they both have interpretations, these interpretations substantially agree.
• Certainly the body should talk about the relatively low quality of the evidence. But it does that. What more is needed there?
• Burt & Tomar 2007 are a reliable source, and are giving the mainstream opinion about why the experience in Europe has been different. It substantially agrees with what Cheng is saying. Aoba & Fejerskov write that "Water fluoridation is by far the most cost-effective public health measure in caries prevention", and this does not disagree with their other statement (which you mention) that we can't fully explain how fluoride works.
• For more, please see #Effectiveness, motivation, biological mechanism, etc. below.

Eubulides (talk) 21:23, 27 December 2008 (UTC)

You said that "followup remarks seem to be arguing against the CDC's conclusion that water fluoridation is associated with fewer cavities". There was nothing in my remarks which argued that. What I do object to is the misleading implication that water fluoridation is necessary for low cavities rates, and that the evidence is incontrovertible. That's what you have been pushing, and that is not supported by any reviews. All the comments which are made to qualify the results, you pull out, even though they are highly pertinent. These include the York review's statements that it was unable to find high-quality evidence, the Yeung review's qualification that no studies controlled for topical fluorides, Pizzo's observation that caries have declined significantly in Europe, ect. Since none of this is mentioned, we can't say that these reviews are being accurately summarized. II | (t - c) 21:25, 30 December 2008 (UTC)

• I don't see anything in the article claiming, or implying, that "water fluoridation is necessary for low cavities rates", much less that the evidence is incontrovertible for that. Obviously the article should not say or imply that; if it does, we should fix it.
• Water fluoridation #Evidence basis says "the quality of the research on fluoridation has been generally low" and Water fluoridation #Effectiveness says "little high-quality research has been done on the cost-effectiveness and solid data are scarce". So the point is already being made, prominently, that high-quality evidence is lacking. We should emphasize this point roughly as much as high-quality reviews do, not more.
• Diving into each review, and pulling out just the negative parts of it, is not the right way to summarize what it says. We need to summarize the whole review, accurately, giving the big picture of what it says. For the big picture, it is quite reasonable to mention that evidence is lacking (which is what the article already says); it is not so reasonable to go into an enormous amount of detail as to which evidence is lacking and why, as that will bring on WP:WEIGHT problems, obscuring the big picture that there's widespread consensus among all reliable sources that fluoridation prevents cavities.

Eubulides (talk) 22:23, 30 December 2008 (UTC)

[edit] Politics

Following up on the discussion about the unsourced part of the lead in #Evidence-basis changes above, I found a recent reliable source on the politics of fluoridation, Armfield 2007 (PMID 18067684), and used it to source the following rewritten version that unsourced part: "and considerable opposition to water fluoridation exists despite its support by public health organizations". I also used the new source to improve Water fluoridation #Politics considerably, and moved the "top 10" point to Effectiveness, where it belongs better. The new version of Water fluoridation #Politics gives considerably more text to opponents of fluoridation than to proponents, but it does so from the mainstream point of view, so I hope that's OK. Eubulides (talk) 21:51, 22 December 2008 (UTC)

The section looks OK, but it could use a bit of balance. Armfield takes the relatively strong position that all scientific opponents are basically quacks, cites the York review selectively, and cites as one of his most authoritative sources that there is no scientific controversy the 1978 issue of Consumer Reports. It's not accurate to portray the opposition like that, when it includes notable and credentialed researchers such as Hardy Limeback and several other members of the recent NAS panel. Incidentally, even though the contentious -> opposition thing is over, I still don't understand how you can say that opposition can exist without contention. I'm guessing that you regard the contentions of mere citizens to be illegitimate? I'm surprised that you didn't notice the spot where Burt & Tomar mention that research scientists were among the early opponents. They note Sutton's methodological critique in 1959. II | (t - c) 01:29, 23 December 2008 (UTC)

I'm wondering if you'd mind answering my question here? II | (t - c) 21:25, 30 December 2008 (UTC)

By "my question" I assume you mean "I'm guessing that you regard the contentions of mere citizens to be illegitimate?". My answer is "no". I thought it was a rhetorical question and therefore did not require answer; my apologies if you intended it to be a serious question. Eubulides (talk) 22:23, 30 December 2008 (UTC)

[edit] Effectiveness, motivation, biological mechanism, etc.

This series of edits has several problems:

• It changed the section header Motivation to Motivation and biological mechanism and added a discussion of the history of fluoride's presumed biological mechanism. As the ungainly title suggests, this is mixing topics. Also, it is better to put historical stuff in the History section; this will allow us to keep the rest of the article up-to-date. I don't see the relevance of a detailed coverage of the dispute over fluoridation's mechanism into this article; this topic may be relevant to Fluoride therapy, but is only marginally relevant here, and it's certainly not relevant to Motivation, as the motivation for water fluoridation is almost entirely independent of how it works.
• It introduced distracting numeric details into the introductory paragraph of Evidence basis, using the following wording "At 1 mg/L 48% of the population is expected to have fluorosis, 12.5% of which is of aesthetic concern." These detailed numbers were introduced only into the part of that paragraph that is negative, which beefed it up and introduced WP:NPOV problems. There is no need for that level of detail in the brief summary; it should be put into the detailed section.
• Furthermore, the numbers are not correct: they understate the amount of fluorisis of aesthetic concern by more than a factor of two.
• Yeung 2008 (PMID 18584000) summarized those numbers in a different way, which is more useful: it gave the number needed to harm (NNH) for fluoridation versus no fluoridation. (This way was also used in the York review.)
• It removed the lead sentence of Effectiveness, thus making the section harder to follow.
• It adds prominence to the York review, mentioning it by name while not mentioning any other reviews by name. In its discussion of the York review it repeats the review's conclusions, which are already discussed; this overemphasis adds NPOV concerns. There is no need to emphasize the York review to this degree: it is not a revolutionary review nor (due to its age) is it the best and most reliable review right now. Any direct mention of it in the text should be in the History section.
• There is no need to give details like "26 studies met its inclusion criteria, all but 3 of which were 'before and after' studies" for the York review, when details like that are not given for other reviews.
• It relegates the more-recent Yeung review to a mere update of the York review. This is an inaccurate summary of the Yeung review. Yeung based its work on effectiveness on the York review's method, but it covered areas that the York review did not, and it refers to many more studies than jsut "one additional relevant study".
• It introduced discussion of that one study, without citing it. There is no good reason to single out that one study and discuss it in detail here; as per WP:MEDRS we should be summarizing reviews, not individual studies. If we do discuss it, we should cite it.
• It inaccurately summarizes the mainstream opinion about why the water fluoridation experience has been different in Europe. The mainstream opinion is that this is because of the other use of fluorides there, even if we don't fully understand how fluoridation works.
• It inserts text like "some believe" and "is believed to" in text supportive of fluoridation, while omitting qualifiers like that in front of text that is critical. This is clearly a POV problem.
• There's no reason, except perhaps in the History section, to talk about the obsolete theory that fluoride operates primarily preeruptively.
• The paragraph starting "Worldwide, a decline in tooth decay has been observed regardless of water or salt fluoridation" contains a string of claims that omit important caveats in the underlying sources and, together, presents a misleading summary of what is known about fluoridation. For example, the very first word in that paragraph, "Worldwide", is completely inaccurate: Box 1 (pp. 699 and 700) of the cited source (Cheng et al. 2007, PMID 17916854) is clearly talking only about EU countries, not about fluoridation worldwide.
• The statement "Water fluoridation has been regarded as extremely cost-effective for the past fifty years" understates the source, Pizzo et al. 2007 (PMID 17333303), which says that water fluoridation has been considered "the most cost-effective measure for the control of caries at the community level".
• The statement "Fluoridation is also believed to increase the equitability of caries prevention" is not supported by the cited source (Pizzo et al.) which says nothing about belief.
• The statement "The dental profession has not been able to fully explain this decline through the use of fluorides" is a inaccurate summary of the cited source, Aoba & Fejerskov 2002, which says that the dramatic decline in dental caries "has occurred without the dental profession being fully able to explain the relative role of fluoride in this intriguing process". That is, Aoba & Fejerskov imply that fluoride can entirely explain the dramatic decline in dental caries, even if we don't understand its mechanism fully; but the statement in Water fluoridation makes it sound like the decline in caries has occurred for reasons unknown, and we can't explain it with fluoridation (an implication that Aoba & Fejerskov do not make).

To help address these problems, along with some more-recently added changes alleging involvement by nefarious industries and Nazis, I have just now installed a series of edits, the most substantial was this one for Water fluoridation #Effectiveness. The result is by no means flawless, but I hope it is an improvement. Eubulides (talk) 21:23, 27 December 2008 (UTC)

Is there a reason that you don't like numbered bullets? It makes it less easy to reference your points. I changed it before, but since you're adopting that, I want to know why before I change it again.

• Motivation and mechanism are inextricably linked, and therefore there's a decent reason to discuss them together. Clearly fluoride's use is motivated by its mechanism? They can be separated if it's a big deal for you, but originally water fluoridation was believed to work almost entirely preeruptively and thus only in children, as the FWRG notes. This is a major fact related to mechanism, and deserves to be noted in that section. If we can't agree to include some historical context in the Mechanism section, we'll have to do mediation or I'll have to open a RfC.
• The Yeung review was a broad review of fluoridation. For efficacy, it relied basically entirely upon the York review, although it did find 1 additional study, which I described and which did not support water fluoridation. Since the Effectiveness section is focused on water fluoridation rather than other types, York is clearly superior to Yeung on water fluoridation's effectiveness. Yeung can be viewed as a collection of reviews, whereas York is a much more focused review of water fluoridation's effectiveness. This can be seen on page 33 of the report, where Yeung writes "[o]nly one additional relevant original study was identified in the current review and this did not change the conclusion of the existing systematic review [York]". For water fluoridation, it cites only two reviews that additional study -- and it says over and over that the York review was the superior one.
• Burt & Tomar do not cite data (or anything) for their assertion. Thus, it should not be stated as fact, as it is now. If something is supported by a careful, focused review of data, as the York review's conclusions are, and cited indisputably, then I'm fine with writing it as fact. It's not POV, and I don't see why we need to start throwing around accusations.
• One can interpret Aoba either way, but clearly if one can't explain fluoride's role in the decline, it's premature to assert conclusively that fluoride does explain the role. In any case, my version did cite Cheng in saying that the decline is largely attributed to fluorides, but mainly topical ones, and was more accurate in that it noted that the research isn't conclusive. If it isn't conclusive, or it's arguable, then we shouldn't put it in the article as if it is conclusive. That's the general problem with your approach to the Effectiveness section.

Should I just go ahead and try to do mediation or a RfC, or can we reach a happy medium on this Effectiveness section which notes the basic qualifications about the evidence raised by York's review, or even by Yeung's review (that the studies did not control for topical fluorides)? Relying largely on the Yeung review when the York review is indisputably the highest-quality review of water fluoridation's effectiveness seems like suffers from WP:RECENTISM bias. We know how up to date the York review is because Yeung did a literature search with its criteria, and found only 1 additional study, which was poor and did not support water fluoridation. Whether the York review is revolutionary or not, no substantive critique has appeared in 8 years; in fact there has been the exact opposite response. II | (t - c) 21:25, 30 December 2008 (UTC)

• In the past, I've found that numbered bullets don't work well on talk pages: people insert text between the numbers and then the numbers go haywire. Anyway, the numbers don't help all that much. It's no big deal either way; please feel free to use numbers in your comments.
• Motivation is "inextricably linked" only in the sense that it's related to fluoridation, and fluoridation is linked to its mechanism. Motivation is equally "inextricably linked" to history, and to the evidence basis, and to politics, and to all the other sections of Water fluoridation. Overall it's better to put historical matters in the History section, to avoid cluttering up the other sections with obsolete stuff. It is certainly better to avoid cluttering up the Motivation section with arguments about why part of long-ago arguments supporting fluoridation were incorrect.
• York is not at all "clearly superior" to Yeung on effectiveness. Yeung is more recent and has better data. Yeung covers every study that York does, and then some. It's rare for high-quality public-health reviews to be significantly worse than reviews done 8 years before, and Yeung is not an exception to this general rrule.
• Burt & Tomar are expert opinion on this subject, and no reliable source disagree with them. There is no reason to insist on Cochrane Collaboration quality reviews for every point in this article: we should be reporting the mainstream consensus, which we are doing in this case.
• There is a difference between not being able to explain every detail of how fluoride actually works (which we can't), and being able to show that fluoride prevents tooth decay (which we can). It's similar to autism: we don't know the exact mechanism for autism, but we do know (because we've done the science) that autism is highly heritable. This is not a question of interpreting Aoba either way: it is a question of whether mainstream scientific opinion is that fluoride prevents tooth decay, which is what the opinion clearly is.
• As mentioned above, the claim in the older version that "Worldwide, a decline in tooth decay has been observed regardless of water or salt fluoridation, and this decline usually attributed to the use of topical fluorides and perhaps nutrition." (citing Cheng et al. 2007, PMID 17916854) is incorrect. Cheng et al. say nothing about a "worldwide" decline: their claim is only about the EU. Cheng et al. do not attribute the decline to "topical fluorides" in general, but instead said that it was probably "fluoridated toothpastes and other factors".
• I'm not sure what "noted that the research isn't conclusive" refers to. The current version notes that fluoridation research is of low quality. That point needs to be made clearly, but it doesn't need to be repeated over and over.
• I agree that the Wikipedia article should not take sides when reliable sources disagree. But there isn't much disagreement here, among reliable sources.
• I don't know what is meant by "Yeung's review (that the studies did not control for topical fluorides)". I don't see anything to that effect in Yeung's review. Can you supply a page number and/or quote from the published review?
• Obviously further changes can be made in this area: Water fluoridation is by no means perfect. But we need to follow the main outline of what the reliable sources say: we should not be emphasizing just the negative parts (or just the positive parts, for that matter).
• I suggest that you propose further changes to address the concerns you raise, in the light of the above comments. I don't think an RfC or mediation is called for at this point, as I think we're still making progress in improving this article.

Eubulides (talk) 22:23, 30 December 2008 (UTC)

[edit] Moderate quality etc.

This edit added the sentence 'The evidence was of moderate quality, and none of the analyses controlled for other sources of fluoride.', with the edit summary 'Page 37 of Yeung's full report: "it should be noted that the analyses did not take into account the use of other sources of fluoride".' There are several problems with this edit:

• The cited source is the York review (PMID 11021861), not Yeung 2008 (PMID 18584000), so this text is incorrectly sourced.
• The comment on page 37 of the Yeung full report does not apply to the results of the York review. It applies only to Table 12 (page 38) of the Yeung full report. Pulling that comment out of the Yeung full report and placing it here, out of context, makes it appear that Yeung's comment applies to all of the York study, which it does not.
• The comment on page 37 of the Yeung full report says nothing about "moderate quality", so that part of the text does not seem to be sourced.
• Water fluoridation should not be reach down into the full Yeung report (which was not published in a refereed journal) to emphasize details that Yeung himself did not feel worth emphasizing in the published peer-reviewed article that Water fluoridation is citing. As per WP:MEDRS, the article should rely on peer-reviewed review articles in refereed journals for information about weight.

Eubulides (talk) 01:11, 31 December 2008 (UTC)

Neither the CDC nor Burt & Tomar are published in peer-reviewed articles, so it seems a bit like wikilawyering to say that a government agency report, similar to the CDC's reports, should not be cited. You really want to stick with that argument? I put the Yeung comment in there to answer your question, but I was also aware that the York review supported the statement I put in. The York review states the following:

The most serious defect of the studies of possible ben­eficial effects of water fluoridation was the lack of appropriate design and analysis. Many studies did not present an analysis at all, while others did not attempt to control for potentially confounding factors. Age, sex, social class, ethnicity, country, tooth type (primary or permanent), mean daily regional temperature, use of fluoride, total fluoride consumption, method of measurement (clinical exam or radiographs, or both), and training of examiners are all possible confound­ing factors in the assessment of development of dental caries.

Although I can't find it off the top of my head, I know that the only confounding factors controlled by any of the studies were age and possibly one other thing (not fluorides). I'll switch the statement to be closer to York's review, though. Yeung does relate York's statement that the evidence is of B quality (moderate quality, moderate bias). Use your PDF find function for any of the prior words. Also, Yeung does appear to be referring to all the York review's studies when he says none controlled for topical fluorides, contrary to your statement. II | (t - c) 01:36, 31 December 2008 (UTC)

• Yes, we should prefer high-quality review articles, as per WP:MEDRS. However, the CDC report in question (PMID 11521913) is a special case: it is published in Morbidity and Mortality Weekly Report, which, although not formally peer-reviewed, has a reputation higher than many peer-reviewed medical journals. For example, Olmsted et al. 2006 (PMID 17161735) lists MMWR as the equal of the best peer-reviewed journals as a source of information about infection control: it says, "Among nonpeer-reviewed periodicals, most infection control coordinators hold the CDC's MMWR in high regard. It is unique because the content contains science-based public health information and must meet rigorous criteria for publication (such as originality, quality, and timeliness)." WP:MEDRS already lists MMWR in an approving context, and it is the equal of peer-reviewed medical journals for most Wikipedia purposes.
• Burt & Tomar 2007 are published in a high-quality book Silent Victories: The History and Practice of Public Health in Twentieth-Century America (ISBN 0195150694), published by a respected university press (Oxford) and written and edited by prominent mainstream scientists and historians. While not strictly a peer-reviewed review, it's clearly a high-quality source as per WP:RS and WP:MEDRS. If we find a peer-reviewed review in a journal article, that would be better, but Burt & Tomar will do fine for now.
• Thanks for switching the statement to be closer to what the York review says, by replacing ", and none of the analyses controlled for other sources of fluoride" with ". Many studies did not appropriately control for observer bias and confounding factors, and many failed to use appropriate statistical techniques". I checked the York review (PMID 11021861), and found:

• It talked about "reducing potential observer bias" (p. 859) rather than controlling for observer bias.
• It did not mention "failed to use appropriate statistical techniques", or anything close to that that I could see.
• It said (p. 858) "The most serious defect of the studies of possible beneficial effects of water fluoridation was the lack of appropriate design and analysis. Many studies did not present an analysis at all, while others did not attempt to control for potentially confounding factors." When discussing flaws in the studies, we should be emphasizing this defect. The current wording mentions controlling for confounding factors, which is appropriate, but it does not mention design and analysis.

• I used my PDF find function on Yeung 2008 (PMID 18584000) and could not find anything about controlling for topical fluorides. Could you please give an exact quote and/or a page number? Thanks.

Eubulides (talk) 09:23, 31 December 2008 (UTC)

Asking for a third opinion. 01:47, 31 December 2008 (UTC)

Sorry, what exactly is that 3rd opinion being asked about? WP:3O#Active disagreements says "Disagreement as to whether to include critical statements made by a 2000 review, which were less stridently repeated by a 2008 review which largely depended upon the 2000 review." but I don't know which specific critical statements it is referring to. Eubulides (talk) 09:23, 31 December 2008 (UTC)

If we can agree on how it looks now, then I'll take down the 30 request. But generally I think an outside opinion on the entire situation wouldn't hurt. II | (t - c) 01:07, 1 January 2009 (UTC)

I agree that an outside opinion would help; still, it's not clear right now what the outside editor is being asked to look at. Eubulides (talk) 08:05, 1 January 2009 (UTC)

[edit] Caries decline etc.

This series of edits introduces some more problems:

• It introduces the claim "The tooth decay decline in industrialized nations is generally attributed to the use of topical fluorides", citing Pizzo et al. 2007 (PMID 17333303). But Pizzo et al. place an important qualifier on this claim: they are talking only about the decline in caries since the 1970s, not the decline before that.
• A nit: most non-expert readers won't know what a "topical fluoride" is; it needs to be explained.
• It uses the word "but" to oppose Pizzo et al.'s claim to the CDC's claim that the decline in tooth decay in the U.S. since water fluoridation began has been attributed largely to the fluoridation. These claims are not mutually exclusive, and the reliable sources are not opposing them, so we should not oppose them either.
• It inserts the claim "Diminishing returns to fluoride introductions have been observed as topical fluorides became more common, with early studies showing declines of around 50-60 percent and more recent studies in the range of 18-40 percent.", citing the FRWG, but the FRWG does not use the phrase "diminishing returns" and what they do say has nothing to do with with the common meaning of the term "diminishing return" as explained in Diminishing return.
• It inserts the claim "In Europe, many countries have experienced substantial declines in caries without the use of water fluoridation, leading some researchers to speculate that water fluoridation may be unnecessary in industrialized nations.", citing Pizzo et al. But Pizzo et al. do not say "some researchers" or anything like that. This needs to be reworded to avoid saying things that the source does not say. Also, the source says "most European countries", not "many European countries".
• It introduced duplicate citations to Pizzo et al.

I made this further change to attempt to address the above problems. Eubulides (talk) 08:05, 1 January 2009 (UTC)

Your edit looks pretty good. Some comments:

• Clearly there is tension between the CDC's statement that the decline in the US since the 1950s is largely attributed to water fluoridation and Pizzo's statement that the decline since the 1970s is attributed to topical fluorides. But I suppose it's fine the way it is.
• I beg to differ that average readers won't understand that term, but what you added certainly is more precise.
• I can't understand how that could be interpreted as anything but diminishing returns. Please explain how what Pizzo calls a "diminishing benefit" (citing that very same CDC source as well another) caused by the application of more and more of one product on a fixed surface (fluoride) is not a diminishing return. Using the exact same words that the source uses can introduce plagiarism problems. Summarizing with synonyms or well-known conceptual terms such as diminishing returns should not a problem.
• Pizzo et al are researchers, and they are speculating. I think you know that. Could you please explain how this was confusing to you? Certainly it's nothing like original research. Citing the more speculative conclusions of a few researchers with "some researchers" preface is pretty common, and there's nothing wrong with it except that it's awkward stylistically.
• Oh yeah, I meant to do that. Please reintroduce those duplicate citations.

II | (t - c) 09:22, 1 January 2009 (UTC)

• Diminishing returns are when each additional unit of variable input yields less and less output. When applied to water fluoridation, it would mean (I suppose) that each additional mg/mL of water fluoridation would yield less and less reduction in dental caries. But that's not what is being discussed here: the topic is that, in locales where toothpaste fluoridation works better, water fluoridation has less benefits than in locales where toothpaste fluoridation does not work as well. This is a different phenomenon; it is not diminishing returns.
• For Water fluoridation to say that Pizzo et al. are researchers, and that they are speculating, we would need a reliable source saying that they are researchers, and that they are speculating. We don't have such a source, and in the absence of such a source we shouldn't put material like that into the article.
• Even if we had a source for that claim, we shouldn't include it. People read Water fluoridation to find out about water fluoridation, not to find out about Giuseppe Pizzo. More generally, the main text of articles should not mention the identity of sources, as this clutters things up unnecessarily. There are exceptions for notable and/or controversial research, but nothing in Water fluoridation rises to that level.

Eubulides (talk) 19:39, 1 January 2009 (UTC)

• In the context of fluoride, it means that if you use brush your teeth with fluoridated toothpaste every day, drink fluoridated water, and use a fluoridated rinse or varnish, each one has a weaker and weaker effect because you're trying to add more fluoride when fluoride is already there and doing its thing. That's what Pizzo is referring to as a "diminishing benefit". And that is what's being discussed here: water fluoridation has less benefits in areas where toothpastes work better not for a mysterious reason, but simply because toothpastes are more commonly used and applied in areas where it "works better". The article doesn't need to be changed, but I'm surprised you're pushing back so hard against this basic, ubiquitous phenomenon. II | (t - c) 20:57, 1 January 2009 (UTC)

But that's now how fluoride works. It's not a question of adding more and more fluoride, and getting less and less benefit for each addition. On the contrary, it's a question of obtaining an optimal level; for some locations you need to remove fluoride, not add it. So it's not a case of diminishing returns in the classic sense (as described in Diminishing returns). Mentioning the phrase "diminishing returns" here might give the inexpert reader the misimpression that more fluoride is always better. Eubulides (talk) 00:09, 2 January 2009 (UTC)

"Oh yeah, I meant to do that. Please reintroduce those duplicate citations." By "duplicate citations" I meant that this version of the References section contains two copies of the citation to Pizzo et al. 2007 (PMID 17333303), once as reference [14] and once as reference [18] (the latter cited twice). In this edit I coalesced those two copies into a single copy; in the current version of References it is reference [14], cited three times. The total number of citations in the article did not change; it is only the number of copies in References has been reduced from 2 to 1. Eubulides (talk) 20:30, 1 January 2009 (UTC)

I know, I was joking. I forgot to add the / when referencing Pizzo and the bot added the full cite. Could we try to stick to things that matter rather than careless mistakes? Your focus on the above mistake makes you seem a bit robotic. I'm not sensitive about it, and I'll try to make less in the future, but it's not worth raising on the talk page. II | (t - c) 20:57, 1 January 2009 (UTC)

[edit] Borrow foundation sources

This edit was reverted by Trendley (talk · contribs) without comment on this talk page, the change log being "Milk fluoridation topic has been subject of discussion already!" I just now searched this talk page and its archives looking for discussion of "milk" and "Borrow" (for the Borrow foundation), and came up dry: I don't see anything relevant to the change.

The edit did four things:

• For less-reliable sources (self-published web pages by the Borrow Foundation) it substituted more-reliable ones (medical journal articles).
• It mentioned that fluoridated milk has been aimed at children, not adults.
• It mentioned that a Cochrane Collaboration review found insufficient evidence to support the practice.
• It removed detailed discussion of a dated example from Beijing.

All these changes seem to be improvements to me. None of these changes, as far as I can see, have been discussed on this talk page before now. On the theory that it's the dated example whose removal was being objected to, I reinstalled the change with one further improvement: an addition that mentions as an example the fluoridation of milk powder in rural Chile. I hope this suffices to remove the objection, whatever it is. Eubulides (talk) 18:45, 3 January 2009 (UTC)